When making an endoscopic examination of a particular site in a patient's body, it is common for the physician to take at least one tissue sample from that site for analysis. A variety of such devices for taking of small tissue samples are in use. In general, such biopsy devices include a small diameter elongate catheter-like instrument adapted to be passed through a lumen in the endoscope, the device being longer than the endoscope so that its distal end can extend out of the distal end of the endoscope. The distal end of the device typically is provided with a pair of sharp jaws that can be open and closed to cut away a small sample of tissue to be investigated. The opening and closing of the jaws is controlled manually by the physician by manipulating controls at the proximal end of the device.
Such endoscopic biopsy procedures involve repeated insertion and removal of the device through the narrow endoscope channel when it is necessary to take multiple biopsies. The device must be sufficiently rugged to withstand such repeated use yet must be constructed so that it will not cause damage to any of the parts of the endoscope as it is advanced through the endoscopic channel.
Among the difficulties presented with such devices is that they typically are relatively expensive, partly because of the intricate work required to manufacture the miniature jaws and jaw actuating mechanisms. Additionally, the cutting edges of the jaw tend to become dull with use and require periodic sharpening, a procedure that involves considerable skill and a high degree of care because of the miniature size of the jaws. Very slight errors in sharpening procedure can impair seriously the effectiveness of the jaws. Often, it is only possible to sharpen such a device a few times before its dimensions are so changed that it is no longer effective. When that occurs, it is common practice to replace the entire device. Also among the difficulties presented by such endoscopic biopsy devices is that they are difficult to clean and sterilize. The jaw mechanisms define numerous crevices. Additionally, the elongate body of the device is made from a highly flexible tightly wound helical coil which provides numerous crevices for retaining debris or contaminants and the like.
It is believed that there is a need for a low cost, simple, disposable endoscopic biopsy device. It is among the general objects of the invention to satisfy that need.